The LCD (liquid crystal display) is an electrical element that applies to a display device electrical/optical properties of liquid crystal having intermediate physical properties between a solid and a liquid, and displays an image by controlling the amount of light transmitting the liquid crystal.
That is, the LCD is an electrical element that uses a change in transmissivity of the liquid crystal responsive to an applied voltage and changes various electrical information generated by various devices to visual information and transmits the visual information in visual images.
Since the LCD is not a self-illuminating display device, the LCD essentially requires light from an exterior source to display the images. In order to supply the light to the LCD, the LCD includes a BLU (backlight unit) disposed at a rear surface of the LCD as a light source. The BLU is a composite body including a power source circuit for driving the light source and other accessories providing an even plane light source.
The BLU is mounted with a light source such as an LED (light emitting diode) and a PCB (printed circuit board) largely employs a metal material for sustaining heat radiated from a light source element. However, if the heat generated by the light source element is not properly dissipated, there is a risk of the light source element being broken and shortened in life.
FIG. 1 is a cross-sectional view of a heat-radiating PCB 10 and a blanket 40 mounted at a chassis 50 which is lightguide path of a backlight unit.
Referring to FIG. 1, the blanket 40 for fixing the heat-radiating PCB 10 to the chassis 50 is separately prepared, and bonded using TIM (thermal interface material. 20). That is, the heat-radiating PCB and the blanket are bonded to the chassis used as a lightguide path using the TIM.
However, in a case the heat-radiating PCB 10 and the blanket 40 are separately manufactured and bonded using the TIM 20, there is a disadvantage of the degraded Heat Transfer Coefficient (Ratio) caused by the TIM 20 to decrease the heat-radiating effect.
FIG. 2 is a plan view of a heat-radiating PCB according to prior art.
Referring to FIG. 2, the heat-radiating PCB includes a driving unit 60 driving by being divided into three driving regions 60a, 60b, 60c, a reference electrode 70 commonly supplying a power source to the driving unit 60 and a plurality of individual electrodes 75 supplying a power source to each driving region 60a, 60b, 60c. 
The reference electrode 70 and the driving unit 60 are connected to a first electrode line 80 while a first electrode line 85 is connected to the plurality of individual electrodes and the driving regions 60a, 60b, 60c. A driving area 120 includes a plurality of LEDs.
The conventional heat-radiating PCB 10 is configured to have a driving area divided into three driving regions 60a, 60b, 60c, whereby it is difficult to perform dimming and scanning functions and to control the driving regions in a segmented illumination.
The conventional heat-radiating PCB 10 also suffers from disadvantages in that the electrodes 70, 75 and the electrode lines 80, 85 are formed on the same planar surface to increase the width (P) of the PCB 10, making it difficult to miniaturize the PCB, and the life of the PCB can be shortened by the heat generated by the current flowing in the electrode lines 80, 85.